1. Field of the Invention
This invention relates to the field of heart surgery. In particular, this invention provides a cardiopulmonary bypass device and method for returning oxygenated blood to the aorta artery, after the blood has been drawn from, for example, the vena cava veins or right atrium of a heart. The cardiopulmonary bypass device and method of the invention can advantageously be used in cardiopulmonary bypass performed during minimal invasive cardiovascular surgery with cardioplegia.
2. Description of the Prior Art
Cardiac surgery relates to surgical procedures performed on a patient""s heart. To perform such cardiac procedures, the heart is sometimes stopped so that the desired surgical procedure can be performed on a generally stationary heart. Such stopping of the heart is often referred to as cardioplegia. To maintain blood circulation through a patient body while the heart is stopped, a cardiopulmonary bypass is often employed. Traditionally, in the case of open heart surgery, the chest is opened using a median sternotomy to gain access to the heart. In open heart surgery, access to, for example, the aorta, for cross clamping purposes for pulmonary bypass and/or the like, is readily provided. Before stopping the heart, an arterial cannula is typically connected in fluid flow communication with the aorta artery and a venous cannula is typically connected in fluid flow communication with the superior and inferior vena cava veins. The arterial cannula and the venous cannulas typically define apertures of about 0.5 inch in diameter. The cannulae are typically connected to a cardiopulmonary bypass (CPB) system so as to perform cardiopulmonary bypass. In cardiovascular bypass, blood is drawn from the vena cava veins of a patient undergoing coronary surgery. Thereafter, the blood is passed through a venous reservoir and through an oxygenator or artificial lung where it is oxygenated. A major portion of this oxygenated blood is typically filtered and returned to the patient""s aorta artery for circulation throughout the body. Thus, the CPB system typically takes over the functions of the heart and the lungs of the patient by oxygenating and pumping the blood through the patient body while the patient""s heart is bypassed and stopped.
Once the CPB system is operatively connected to the patient and brought into operation, the ascending aorta artery is typically cross clamped to isolate the coronary arteries from the rest of the arterial system. Thereafter, cardiac arrest is induced by typically injecting 500 to 1000 cc of cardioplegic solution into an aortic root using a needle or cannula which pierces the wall of the ascending aorta artery upstream of the cross clamp. Cardioplegic solution typically comprises aqueous solutions of potassium chloride and often contains additional substances such as dextrose, glutamate, aspartate, and various other electrolytes such as Ca+2 and Mg+2. The punctures of the 0.5 inch diameter venous cannulae and the arterial cannula on the two vena cava veins and on the aorta artery, respectively, often require repair before the heart can be restarted. This is typically accomplished by means of suturing. After such suturing, and after the heart is then restarted, the sutures need to be closely monitored so as to ensure that the punctures have been adequately repaired thereby to inhibit rupturing and internal bleeding after completion of the surgery.
Typically, the foregoing procedure does not present a large problem when open chest heart surgery is to be performed since the surgeon is provided with ready access to the vena cava veins and the aorta artery. However, it can happen that the surgical procedure is to be performed in a manner other than open surgery. Accordingly, in such a case, and where pulmonary bypass is required, ready access to the vena cava veins and the aorta artery may not be readily available. This is typically the case where, for example, the surgical procedure is to be performed in a minimally invasive surgical manner.
Minimally invasive surgery is a relatively recent and very important development in the field of surgery. Generally, minimally invasive surgical techniques use endoscopic or transluminal surgical approaches in performing surgery so as to inhibit trauma and morbidity associated with relatively more invasive surgical techniques such as the open heart surgical technique described above. Minimally invasive surgical techniques have been, and are in the process of being, developed to perform surgical procedures by means of endoscopic or transluminal techniques. It is desirable that myocardial protection and cardiopulmonary support are catered for in a minimally invasive manner to obviate the need to open the patient""s chest, so as to permit the cardiac procedure to be conducted fully in a minimally invasive manner. Current methods of cardioplegia and performing cardiopulmonary bypass do not adequately meet this desire as evidenced in the following prior art U.S. patents, the full disclosures of which are fully incorporated herein by reference: U.S. Pat. No. 4,712,551 to Rayhanabad; U.S. Pat. No. 4,979,937 to Khoransani; U.S. Pat. No. 5,190,538 to Fonger et al.; U.S. Pat. No. 5,466,216 to Brown et al.; and U.S. Pat. No. 5,695,457 to St. Goar et al.
U.S. Pat. No. 4,712,551 to Rayhanabad discloses a vascular shunt having a plurality of branches. The various embodiments of the vascular shunt are depicted in FIGS. 1 and 8 of this patent.
U.S. Pat. No. 4,979,937 to Khoransani discloses a plurality of small cannulas connected to Y-connectors and to larger cannulas for providing blood flow during aortic procedures. More specifically, and as can best be seen with reference to FIGS. 1 and 2 of this patent, there is seen an intercostal and lumbar perfusion apparatus having a main member and a plurality of side members communicating with the main member via a Y-connector. The apparatus disclosed in this patent provides blood flow to distal organs and intercostals during aortic surgery.
U.S. Pat. No. 5,190,538 to Fonger et al. discloses a cannula within the left atrium of the heart for draining blood and returning it via an arterial cannula after passing through an extra-corporeal pump. The atrium of the heart is pierced by a needle assembly to enable insertion of a catheter and the cannula.
U.S. Pat. No. 5,466,216 to Brown et al. discloses a pair of cannulae, respectively, inserted into the aortic root and the coronary sinus of a heart (see FIG. 1). A system or assembly interconnects the two cannulae for delivery of blood and cardioplegic solution to the aortic root for antegrade infusion or to the coronary sinus for retrograde infusion.
U.S. Pat. No. 5,695,547 to St. Goar et al. discloses a complete cardioplegia and cardiopulmonary bypass system. The devices disclosed in this patent induce cardioplegic arrest for myocardial protection during cardiac surgery by direct perfusion of the coronary arteries using a transluminal approach from a peripheral arterial entry point.
The prior art above does not teach a method or an apparatus whereby cardiopulmonary bypass can be performed without having to repair cannula punctures in the aorta artery and the vena cava veins after termination of a cardiopulmonary bypass procedure.
It is an object of the present invention to provide a method of performing cardiovascular bypass for cardiac surgery with cardioplegia.
It is another object of the present invention to provide a method of performing cardiopulmonary bypass for minimal invasive cardiovascular surgery with cardioplegia.
It is another object of the present invention to provide a cardiopulmonary bypass system.
It is another object of this invention to provide an apparatus and method whereby cardiopulmonary bypass can be performed without having to repair punctures in the aorta after the cardiopulmonary bypass has been completed. It is a further object of the invention to provide a cardiopulmonary bypass apparatus and method which also inhibits having to repair punctures in the vena cava veins upon completion of the cardiopulmonary bypass procedure.
According to one aspect of the invention, a method of performing a cardiopulmonary bypass procedure is provided. The method includes accessing a source of blood in a patient body from which source the blood is to be passed through a cardiopulmonary bypass machine, drawing blood from the source through the cardiopulmonary bypass machine and introducing the blood into an aortic artery of the patient body through a plurality of separate passages, after the blood has been passed through the cardiopulmonary bypass machine.
According to another aspect of the invention, there is provided a cardiopulmonary bypass system comprising a cardiopulmonary bypass machine, a tubular member coupled to an outlet port of the cardiopulmonary bypass machine and a plurality of separate needle members connected in fluid flow communication with the tubular member, the needle members being arranged to be connected in fluid flow communication with an aortic artery, during a cardiopulmonary bypass procedure.
According to yet a further aspect of the invention, there is provided a method of performing cardiovascular bypass for cardiac surgery with cardioplegia, the method comprising the steps of:
a) inserting a plurality of needle members into a right atrium of a patient""s heart;
b) flowing blood from the right atrium of the patient""s heart, through the plurality of needle members, and to a cardiopulmonary bypass machine where the blood is oxygenated to produce oxygenated blood; and
c) flowing the oxygenated blood of step (b) into an aorta artery extending from the patient""s heart such that cardiovascular bypass is performed for cardiac surgery with cardioplegia.
The immediate foregoing method may additionally comprise inserting, prior to the flowing step (c), a plurality of a aorta needle members into the aorta artery extending from the patient""s heart. The flowing step (c) may comprise flowing oxygenated blood through the aorta needle members and into the aorta artery. Preferably, the aorta artery is occluded (e.g., such as by pinching the aorta artery) at a location between the patient""s heart and the aorta needle members. In a preferred embodiment of the invention, the inserting step (a) includes inserting the needle members into a right auricle of the patient""s heart. The needle members may each be dimensioned with an inside diameter such that each needle member has blood flowing therethrough at a respective volumetric flow rate. Similarly, the aorta needle members may each be dimensioned with an inside diameter such that each aorta needle member has blood flowing therethrough also at a respective volumetric flow rate. The needle members may communicate with a tubular member which preferably may be dimensioned with an internal diameter such that the blood flowing through the tubular member has a volumetric flow rate that is approximately equal to the sum of the respective volumetric flow rates of the blood flowing through the plurality of needle members. Similarly, the aorta needle members may communicate with a tubular member that may be dimensioned with an internal diameter such that the oxygenated blood flowing through the tubular member has a volumetric flow rate that is approximately equal to the respective volumetric flow rates of the oxygenated blood flowing through the plurality of aorta needle members.
According to yet another aspect of the invention, there is provided a method of performing cardiopulmonary bypass for minimal invasive cardiovascular surgery with cardioplegia, the method comprising the steps of:
(a) providing a plurality of first needle members communicating with a first tubular member which is coupled to a cardiopulmonary bypass assembly;
(b) providing a plurality of second needle members communicating with a second tubular member which is coupled to the cardiopulmonary bypass assembly;
(c) providing a plurality of third needle members communicating with a third tubular member which is coupled to the cardiopulmonary bypass assembly;
(d) inserting a plurality of first needle members into a superior vena cava vein extending to a heart of a patient;
(e) inserting a plurality of second needle members into an inferior vena cava vein extending to the heart of the patient;
(f) inserting the plurality of third needle members into an aorta artery extending from the heart of the patient;
(g) occluding the superior vena cava vein at a location between the first needle members of step (d) and the heart of the patient, causing blood to flow from the superior vena cava vein, through the first needle members, and through the first tubular member to the cardiopulmonary bypass assembly where the blood is oxygenated;
(h) occluding the inferior vena cava vein at a location between the second needle members of step (e) and the heart of the patient, causing blood to flow from the inferior vena cava vein, through the second needle members, and through the second tubular member to the cardiopulmonary bypass assembly where the blood is oxygenated;
(i) occluding the aorta artery at a location between the third needle members of step (f) and the heart of the patient; and
(j) flowing oxygenated blood from the cardiopulmonary bypass assembly, through the third tubular member, and through the third needle members and into the aorta artery such that cardiopulmonary bypass is performed for minimal invasive cardiovascular surgery with cardioplegia.
According to yet a further aspect of the invention, there is provided a cardiopulmonary bypass system comprising a cardiopulmonary bypass assembly, a first tubular member coupled to the cardiopulmonary bypass assembly and a plurality of first needle members coupled to the first tubular member, a second tubular member also coupled to the cardiopulmonary bypass assembly and a plurality of second needle members coupled to the second tubular member.